During manufacture of semi-conductors and semi-conductor microcircuits, it is frequently necessary to coat the materials from which the semi-conductors and microcircuits are manufactured with a polymeric organic substance which is generally a photoresist, i.e. a substance which forms an etch resist upon exposure to light. Subsequently, the polymeric organic substance must be removed from the surface of the organic substrate which is typically a silicon dioxide coated silicon wafer and may also contain metallic microcircuitry, such as aluminum, on the surface. Therefore, there is a need for improved stripping compositions which will remove the polymeric organic substance from the coated inorganic substrate without corroding, dissolving or dulling the surface of the metallic circuitry or chemically altering the inorganic substrate.
Organic stripping agents comprising aromatic solvents and basic amines are known for removing organic substances from metallic inorganic substrates. While these stripping agents are effective in removing the polymeric substances, they also have the tendency, especially in the presence of water to corrode the metal, particularly copper, aluminum and titanium. It has been proposed in some organic stripping compositions to use hydrogen fluoride to reduce the rate of metal corrosion. However, hydrogen fluoride is harmful to the environment, attacks titanium and creates disposal problems.
Other known inhibitors such as .beta.-napthol, glucose, resorcinol, pyrogallol and benzotriazole have been found to be ineffective to inhibit the pitting of copper when used with a stripping composition comprising organic polar solvents and basic amines.
U.S. Pat. No. 4,617,251 to Sizensky which is herein incorporated by reference, discloses a stripping composition in which the inhibitors of the present invention can be utilized.
British application No. 8428587 discloses stripping compositions comprising amides and amines which can be used with the inhibitors of the invention.
It is an object of this invention to provide improved organic stripping compositions which cleanly and efficiently remove organic photoresist materials from aluminized inorganic substrates, particularly aluminized silicon dioxide, without causing substantial etching of the inorganic substrate or corrosion and dulling of the metallic circuitry on the surface of the inorganic substrate, even after repeated use at elevated temperatures.
It is also an object of this invention to provide a method for removing polymeric organic substances from the surfaces of aluminized inorganic substrates, particularly aluminized silicon dioxide, without causing etching of the inorganic substrate or corrosion and dulling of the metallic circuitry on the surface of the inorganic substrate.